Priority is claimed to Patent Application Number 2001-33911 filed in Rep. of Korea on Jun. 15, 2001, herein incorporated by reference.
1. Field of the Invention
The present invention relates to passive devices and modules for a transceiver, and a manufacturing method thereof, and more particularly, to passive devices and modules for a transceiver in which capacitors, inductors and etc. are formed on and under a substrate, respectively, using a Micro Electro Mechanical System (MEMS) technique, and connected to each other to form a circuit, and a manufacturing method thereof.
2. Description of the Related Art
With the improvement of radio communication techniques, techniques for improving the communication quality of mobile communication systems and downsizing the mobile communication systems have been developed. Also, a transmitting and receiving method for the radio communication systems has been developed with the separate use of frequencies in several bandwidths such as in code division multiple access (CDMA) mode using frequencies in a bandwidth of 900 MHz, and personal communication system (PCS) mode using frequencies in a bandwidth of 1.8 GHz and etc. Therefore, the downsizing of the radio communication systems is more required with use of transceivers using multi-bands.
To downsize personal mobile communication systems, it is most important to reduce the sizes of passive devices, which take up the most space in personal mobile communication systems. Since passive devices used in general mobile communication systems are mostly discrete devices and take up a lot of space on a substrate, they increase the area required for chip mounting and the manufacturing cost. In particular, inductors take up a great deal of space and degrade communication quality.
To solve the above-described problems, it is a first object of the present invention to provide passive devices and modules for a transceiver which are integrated on and under a substrate using a MEMS technique.
It is a second object of the present invention to provide a method of manufacturing the passive devices and the modules.
Accordingly, to achieve the first object, there is a passive device for a transceiver. The passive device includes a semiconductor substrate or a dielectric substrate, at least one capacitor, at least one inductor, a viahole, a metal electrode, radio frequency signals, a radio frequency ground, and a packaging substrate. The at least one capacitor is formed on a first surface of the substrate. The at least one inductor is formed on a second surface of the substrate that is opposite to the first surface. The viahole penetrates through the substrate. The metal electrode is formed on the viahole and electrically connects the capacitor on the first surface and the inductor on the second surface. Radio frequency signals are for the inductor and the capacitor. The radio frequency ground is formed on the substrate and isolated from the radio frequency signals. The packaging substrate is bonded on the first surface or the second surface of the substrate, having a cavity covering a structure on the bonded surface of the substrate.
To achieve the second object, there is provided an integrated module for a transceiver. The integrated module includes a semiconductor substrate or a dielectric substrate, capacitors, inductors, viaholes, metal electrodes, radio frequency input and output signals, radio frequency grounds, and a packaging substrate. The capacitors are formed on a first surface of the substrate. The inductors are formed on a second surface of the substrate that is opposite to the first surface. The viaholes penetrate through the substrate. The metal electrodes are formed on the viaholes and electrically connect the capacitors on the first surface and the inductors on the second surface. The radio frequency input and output signals are for the inductors and the capacitors. The radio frequency grounds are formed on the substrate and isolated from the radio frequency input signals. The packaging substrate is bonded on the first surface or the second surface of the substrate, having a cavity covering a structure on the bonded surface of the substrate,
Here, a circuit is formed of the capacitors, the inductors, the viaholes, the metal electrodes, and the radio frequency input and output signal lines. The circuit includes a radio frequency selector, duplexers, transmission band-pass filters, and reception band-pass filters. The radio frequency selector is composed of a high-pass filter and a low-pass filter. The duplexers include transmission filters that transmit a signal to the radio frequency selector and are composed of band-pass filters, and reception filters that receive a signal from the radio frequency selector and are composed of band-pass filters. The transmission band-pass filters transmit a signal to the transmission filters via power amplifiers. The reception band-pass filters receive a signal from the reception filters via low noise amplifiers.
To achieve the first and second objects, there is provided a method of manufacturing a passive device and a module for a transceiver. A second surface of a substrate is patterned to form a well for a viahole having a bottom. An inductor is formed on the second surface of the substrate and an electrode is formed on the inner wall and bottom of the well for the viahole. A first surface of a packaging substrate is etched. The first surface of the packaging substrate is bonded to the second surface of the substrate. The first surface of the packaging substrate that is opposite to the second surface of the substrate is cut and flattened to expose a portion of the electrode formed on the bottom of the well for the viahole. An integrated circuit including the capacitor is formed on the first surface of the substrate.